package com.tjh.spring5.testdemo;

import com.tjh.spring5.dao.UserDao2;
import com.tjh.spring5.dao.UserDaoImpl2;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;

/**
 * Create by koala on 2021-02-17
 * day25：JDK动态代理
 */
public class JDKProxyDay25 {

    public static void main(String[] args) {
        //创建接口实现类代理对象
        Class[] interfaces = {UserDao2.class};
        UserDaoImpl2 userDao = new UserDaoImpl2();
        UserDao2 dao = (UserDao2) Proxy.newProxyInstance(JDKProxyDay25.class.getClassLoader(), interfaces, new UserDaoProxy(userDao));
        int result = dao.add(1, 2);
        System.out.println("result:" + result);
    }

}

//创建代理对象代码
class UserDaoProxy implements InvocationHandler {

    //1 把创建的是谁的代理对象，把谁传递过来
    //有参数构造传递
    private Object obj;

    public UserDaoProxy(Object obj) {
        this.obj = obj;
    }

    //增强的逻辑
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        //方法之前
        System.out.println("方法之前执行...." + method.getName() + " :传递的参数..." + Arrays.toString(args));

        //被增强的方法执行
        Object res = method.invoke(obj, args);

        //方法之后
        System.out.println("方法之后执行...." + obj);
        return res;
    }
}